DE102020208993A1 - Method for operating a hand machine tool - Google Patents

Abstract

A method for operating a handheld power tool (100), in particular a rotary impact wrench, with a drive unit (111), a manual switch (128), a control unit (102) and with a release operating mode for releasing a screw connection, in particular a fastening element from a fastening support in which, when the manual switch (128) is actuated, a characteristic variable of the drive unit (111) is at least partially automatically controlled and / or regulated.

Description

The present invention relates to a method for operating a handheld power tool with a drive unit, a manual switch and a control unit.

State of the art

From the DE 20 2011 002 192 U1 a motor control device is already known which is adapted to adjust a speed of a motor.

Disclosure of the invention

The present invention is based on a method for operating a hand power tool, in particular a rotary impact wrench, with a drive unit, a manual switch, a control unit and with a release operating mode for releasing a screw connection, in particular a fastening element from a fastening support, in which a Characteristic of the drive unit is at least partially automatically controlled and / or regulated.

The invention provides a method for operating the handheld power tool with which a user can automatically loosen the screw connection by the user operating the manual switch and thereby automatically controlling and / or regulating the control unit.

In the context of the present invention, a “handheld power tool” should be understood to mean, in particular, a hand-held machine tool, preferably a battery-operated handheld power tool with a rotary hammer mechanism. For example, the handheld power tool can be designed as an impact wrench or as a rotary impact wrench.

The screw connection is a connection between the fastening element and the fastening support, the fastening element being screwed to the fastening support. The fastening element can be a screw, a nut or other comparable rotatable fastening elements. The fastening support can be a plastic fastening support, such as a wall, a metal workpiece, a threaded bolt or other comparable fastening supports or a combination thereof. It is also conceivable that the fastening support is an elastic fastening support, such as a molded part made of rubber.

The handheld power tool has the manual switch and the control unit. The manual switch can be operated by the user using at least one finger in order to control and / or regulate the drive unit of the handheld power tool. The user can control and / or regulate the characteristic variable of the drive unit by means of the hand switch. The manual switch also converts the actuation by the user into an electrical signal and transmits it to the control unit. The control unit receives the electrical signal and controls and / or regulates the drive unit of the handheld power tool. The handheld power tool has the drive unit, wherein the drive unit can also include a gear unit in addition to an electric motor. The gear unit is designed to adapt a speed of the electric motor, in particular to reduce and / or increase it. In one embodiment, the gear unit can be designed as a planetary gear, it also being conceivable that the planetary gear can be shifted. In at least one operating state, the electric motor of the handheld power tool is designed to provide a torque for a drive of a main output element. In one embodiment, the main output element is designed as a main output shaft. The main output shaft preferably runs essentially parallel to a working direction of the handheld power tool. In the context of the present invention, “essentially parallel” is to be understood as an alignment of a direction relative to a reference direction, in particular in a plane.

The parameter of the handheld power tool, which is automatically controlled and / or regulated as soon as the manual switch is actuated, is, for example, a speed of the drive unit, the torque of the drive unit, a voltage of the drive unit or a current of the drive unit, further parameters of the drive motor are also conceivable .

The drive unit, in particular the electric motor, is supplied with energy from an energy supply unit of the handheld power tool. The handheld power tool includes an energy supply unit. The energy supply unit of the handheld power tool is provided for supplying energy to at least the drive unit, in particular the electric motor and the control unit. The handheld power tool is preferably a battery-operated handheld power tool, which can be operated by means of at least one rechargeable battery, in particular by means of a handheld power tool battery pack. As a result, the energy is then provided by the at least one energy supply unit by means of the at least one rechargeable battery. In the context of the present invention, a “handheld power tool battery pack” is intended to mean an amalgamation of at least one battery cell and a battery pack housing are understood. The handheld power tool battery pack is advantageously designed to supply energy to commercially available, battery-operated handheld power tools. The at least one battery cell can be designed as a Li-ion battery cell with a nominal voltage of 3.6 V, for example. In one embodiment of the invention, the at least one rechargeable battery can be arranged fixed to the housing essentially within the handheld power tool housing, in particular attached, in particular mounted. In a further embodiment, however, it is also possible for the at least one battery to be designed as an exchangeable battery, in particular as an exchangeable battery pack. Alternatively, the handheld power tool can be a mains-operated handheld power tool, which can be connected to an external mains socket by means of a power supply cable. The external mains socket can provide a voltage of, for example, 100 V, 110 V, 120 V, 127 V, 220 V, 230 V or 240 V with 50 Hz or 60 Hz, but also a three-phase alternating voltage. The possible configurations of the external mains socket and the associated voltages available are sufficiently known to the person skilled in the art.

The hand machine tool also has a tool holder for connection to an insert tool. In one embodiment, the tool holder is assigned to the main output shaft, in particular connected to it, so that the drive of the main output shaft can be transmitted to the tool holder. The insert tool can be designed, for example, in the form of a screwdriver bit, as a HEX bit or as a socket. In one embodiment, the tool receptacle can be designed as a polygonal internal receptacle, in particular a hexagonal internal receptacle. It is also conceivable that the tool holder is shaped as a polygonal external holder or as a chuck.

In the context of the present invention, “automatically” is to be understood as a process that is carried out by the handheld power tool essentially without any influence from the user.

In a process step, a counterclockwise direction of rotation of the drive unit is set to loosen the screw connection. In this case, the fastening element has a right-hand thread, so that the fastening element is detached from the fastening carrier by means of the insert tool by means of the left-rotating drive unit.

In a process step, a clockwise direction of rotation of the drive unit is set to loosen the screw connection. If the fastening element has a left-hand thread, the clockwise drive unit releases the fastening element from the fastening carrier with the aid of the insert tool.

In a method step, the release operating mode for releasing the screw connection is activated by the control unit receiving at least one signal for activating the release operating mode and releasing the manual switch for actuation. The signal for activating the release operating mode comprises at least one piece of information that the user would like to activate the release operating mode. For this purpose, the user can trigger the signal to activate the release operating mode by means of an input unit with at least one input element of the handheld power tool and / or an external electronic device. For this purpose, the handheld power tool has the input unit with the input element. The input unit can be arranged on the handheld power tool, be connected to the handheld power tool, in particular detachably, or else be designed as an input unit that can be retrofitted. The input element can be designed, for example, as a rotary element, a push element or a sliding element. By actuating the input unit, in particular the input element, the user can trigger the signal for activating the release operating mode. The input unit transmits the activation signal to the control unit in a wired or wireless manner.

The signal for activating the release operating mode can also be triggered and sent by means of the external electronic device. For this purpose, the external electronic device has a communication unit. The external electronic device can be, for example, a smartphone, a tablet or a computer, a cloud-based interface also being conceivable. The user can, for example, use a program, in particular an app, to trigger the signal to activate the release operating mode. The external electronic device then uses the communication unit to send the signal for activating the release operating mode to the handheld power tool. To receive the signal for activating the release operating mode, the handheld power tool includes a communication unit. The communication unit is supplied with energy by the energy supply unit. The communication unit of the hand-held power tool receives the signal for activating the release operating mode and forwards it to the control unit in a wireless or wired manner. The handheld power tool can be switched on or off. The communication unit is designed so that in one switched off state of the hand power tool, the signal for activating the release operating mode can be received. For this purpose, the communication unit can have its own energy supply unit. It is conceivable that the communication unit, upon receipt of the signal for activating the release operating mode, puts the handheld power tool into an operational state.

The communication unit of the handheld power tool is assigned to the handheld power tool, but can also be arranged on the handheld power tool. In addition, it is also conceivable that the communication unit is connected to the handheld power tool, in particular in a detachable manner. Furthermore, it is also possible for the communication unit to be designed as a retrofittable communication unit for retrofitting the handheld power tool. In the context of the present invention, the communication unit of the handheld power tool and of the external electronic device is designed to send and / or receive communication signals. In particular, the communication unit of the external electronic device sends the signal for activating the release operating mode as the communication signal and the communication unit of the hand power tool receives the signal for activating the release operating mode. The communication signals can be wired, via a wire connection or via conductor tracks on a printed circuit board, and / or the communication signals can be transmitted wirelessly. A wireless transmission of the communication signals can be in the form of Bluetooth, WLAN, infrared, near-field communication (NFC) using RFID technology, as well as other wireless transmissions of the communication signals familiar to those skilled in the art. The communication protocols used can be Bluetooth Smart, GSM, UMTS, LTE, ANT, ZigBee, LoRa, SigFox, NB-loT, BLE, IrDA, as well as other communication protocols familiar to those skilled in the art.

In one embodiment, the communication unit of the handheld power tool can have its own energy supply unit for supplying energy. For example, the own energy supply unit can be a battery, in particular a button cell, a capacitor or at least a rechargeable battery.

The control unit receives the activation signal. The control unit is designed to control and / or regulate the handheld power tool.

In a method step, the characteristic variable of the drive unit is at least partially automatically controlled and / or regulated after an impact mechanism, in particular rotary impact mechanism, of the handheld power tool has been activated. The control unit is designed in such a way that it recognizes the activation of the striking mechanism as soon as the drive unit is put into operation. As soon as the control unit has recognized the activation of the striking mechanism, the control unit controls and / or regulates the characteristic variable of the drive unit. This enables the screw connection to be loosened piece by piece with a suitable torque.

In a method step, the release operating mode is carried out from a first point in time t1 to a second point in time t2, the second point in time t2 following the first point in time t1. At the first point in time t1, the release operating mode is started, the drive unit being put into operation by actuating the manual switch. Furthermore, the release operating mode is carried out from the first point in time t1 to the second point in time t2. During the release operating mode, the hammer mechanism is activated in order to loosen the screw connection by hitting the hammer mechanism on the tool holder.

In a method step, the release operating mode is carried out from a start time t0 to a second time t2, the drive unit being activated at the start time t0. The release operating mode is started at the start time t0, the drive unit being activated at the start time t0. Here it is possible that the hammer mechanism can also be activated at the start time t0, depending on the screw connection that the user would like to loosen. The release operating mode is carried out from the starting point in time t0 to the first point in time t1, the striking mechanism being activated at the first point in time t1. Furthermore, the release operating mode is carried out from the first point in time t1 to the second point in time t2 in order to release the screw connection.

In a method step, the release operating mode is deactivated after the second point in time t2. As soon as the second point in time t2 is reached, the release operating mode is deactivated by the control unit. If the user continues to operate the hand switch after the second point in time t2, depending on the state of the fastening means, in particular the screw or the nut, the screw connection can be loosened essentially without a hammer mechanism or the fastening means, in particular the screw or the nut, continues to be activated a torque, in particular a second torque value M2 , applied. For example, the fastening element can be detached from the fastening carrier after the second point in time t2 in such a way that, if the fastening element is further detached from the fastening carrier, the percussion mechanism essentially ceases is activated. This enables the screw connection to be loosened in a controlled manner.

In a method step, the parameter is a speed of the drive unit, at least one torque value M being assigned to the speed, and the torque M at least partially automatically up to a first torque value M1 the hand power tool is changed with a first increase in that the speed of the drive unit is changed. As soon as the hammer mechanism is activated at time t1, the release operating mode can make it possible to change the speed of the drive unit. Depending on the screw connection, the release operating mode can at least partially automatically lower the speed via the control unit and then gradually or continuously up to the torque value M1 increase. It is also conceivable that the release operating mode via the control unit when the striking mechanism is activated, depending on the screw connection, at least partially automatically increases the speed of the drive unit and gradually or continuously until the torque value is reached M1 elevated. The first torque value M1 can be coupled to a first speed limit range. The first torque moment value M1 can bear against the main output shaft, in particular the tool holder. A period of time T1 can be from the start time t0 when the manual switch is actuated to the first time t1. After time t1, the torque value M1 can be achieved by changing the speed of the control unit. The first slope S1 can be a change, in particular an increase, in the torque value M until the torque value M1 is reached. The torque value M1 can be user definable.

The first torque value is in a method step M1 in a range from 10% to 80%, in particular 20% to 70%, very particularly 30% to 65%, of a maximum torque value M3 . The maximum torque value M3 is coupled to a maximum speed of the drive unit.

In one process step, after the first torque value has been reached M1 the speed up to a second torque value M2 the hand machine tool with a second slope S2 changed, especially increased. The second torque value M2 can be higher than the first torque value M1 . It is also conceivable that the second torque value M2 is less than the first torque value M1 is. During a period of time T2 the speed is at least partially changed automatically, in particular increased, until the second torque value M2 is achieved. The timespan T2 can be from the first point in time t1 to the second point in time t2, from which the torque value M2 can be achieved. The second torque value M2 can be coupled to a second speed limit range. The control unit can adjust the drive unit to the second torque value M2 set by limiting the speed at least partially automatically to the second speed limit range. The second torque value M2 can be a maximum available torque in one embodiment. The second torque value can preferably M2 greater than the first torque value M1 be. The second speed limit range is thus greater than the first speed limit range. The timespan T2 can be in a time range from 5 s to 30 s, in particular 10 s to 25 s, very particularly 12 s to 20 s.

The first slope S1 can be adjustable by the user, whereas the second slope S2 can be preset by the release operating mode. This enables the screw connection to be released carefully so that damage, in particular destruction, of the fastening element is avoided.

In a method step, the handheld power tool has the hammer mechanism, with the first torque value being reached M1 the striking mechanism is activated. The hammer mechanism can start from a starting torque value M0 activated, with the starting torque value M0 depends on the mechanical design of the striking mechanism. The hammer mechanism can be activated as soon as a resistance on the main output shaft, which can be applied to the tool holder, reaches the starting torque value M0 exceeds. The hammer mechanism can be designed as the rotary hammer mechanism, as an oil hammer mechanism or as a pneumatic hammer mechanism. The rotary hammer mechanism can be designed as a mechanical rotary hammer mechanism. If when increasing the torque, the starting torque value M0 is reached, the hammer mechanism can be activated so that when the torque on the main output shaft, in particular the tool holder, remains constant or continues to increase, the hammer mechanism can generate torque pulses. Here, “torque pulses” are to be understood as pulses that are generated by the hammer mechanism and transmitted to the main output shaft, in particular the tool holder. So the first torque value can be M1 from the starting torque value M0 , from which the hammer mechanism is activated, and combine the torque pulses in order to enable the screw connection to be loosened in the loosening operating mode.

Alternatively, it is possible for the control unit to recognize after several strikes of the striking mechanism that the striking mechanism is in striking operation, so that the release operating mode sets the torque value M to the first via the control unit Torque value M1 at least partially automatically lowers.

The second torque value is in a method step M2 in a range from 50% to 100% of the maximum torque value M3 . This provides an efficient handheld power tool.

The striking mechanism is in one process step during the period of time T2 activated. So can the torque value M2 from the starting torque value M0 and assemble the torque impulses of the hammer mechanism. With the striking mechanism activated during the period T2 the screw connection can be loosened efficiently.

In a method step, the speed is during the period of time T2 continuously increased. The continuous increase in speed can be progressive or degressive. For example, the speed can be increased linearly, quadratically, logarithmically or exponentially.

In a method step, the speed is during the period of time T2 discreetly increased. The discrete speed increase can be progressive or degressive. In this case, the hammer mechanism can then execute at least two successive blows with essentially the same torque pulse level.

In a method step, after the second torque value has been reached M2 the speed is kept essentially constant, in particular until the striking mechanism is deactivated. During a period of time T3 the speed is kept essentially constant. The timespan T3 can be from the second point in time t2 to a third point in time t3. During the period T3 the screw connection, in particular the fastening element, experiences a torque pulse which has a torque value of M2 corresponds to. The control unit can limit the speed of the drive unit to the second speed limit range, so that during the period of time T3 the second torque value M2 remains set. This enables the screw connection with the second torque value M2 is resolved.

In an alternative embodiment, it is possible for the release operating mode to be ended after time t2 and for the user to release the screw connection essentially without the impact of the hammer mechanism. In this case, the user automatically regulates the speed of the drive unit via the manual switch after the release operating mode has ended, in order to completely release the loosened fastening element from the fastening support.

The first torque value is in a method step M1 and the second torque value M2 preset in the control unit. This enables the user to use the handheld power tool directly to loosen the screw connection.

The first torque value is in a method step M1 and the second torque value M2 adjustable in the control unit. This allows the user to get the first torque value M1 and the second torque value M2 set so that the user can efficiently loosen the screw connection automatically. The user can set the first torque value M1 and the second torque value M2 set by means of the input unit of the handheld power tool and / or by means of the external electronic device.

The second slope is in one process step S2 preset in the control unit. This ensures that the user can automatically loosen the screw connection immediately when the hand switch is operated.

The second slope is in one process step S2 adjustable in the control unit. This allows the user to use the second incline S2 set so that the user can automatically loosen the screw connection depending on the application. The user can choose the second slope S2 set using the input unit of the handheld power tool and / or using the external electronic device.

A maximum speed of the drive unit can be set in one process step. In one embodiment, the user can set the maximum speed by means of the input unit, in particular the input element, and / or the external electronic device.

In one process step, the speed is reduced when the hammer mechanism is activated. For this purpose, at least one torque impulse is required in the method step in order to recognize that the hammer mechanism has been activated. After it has been determined that the striking mechanism is activated, the speed can be reduced in order to apply the following torque pulse from the striking mechanism to the fastening element, i.e. the first torque value M1 to weaken. This makes it possible for the loosening of the fastening element to be continued cautiously in order to avoid damage, in particular destruction, of the fastening element.

In one method step there is a change in the speed of the drive unit during the period of time T1 and / or a period of time T2 adjustable. Depending on the application, the user can set the speed change by means of the input unit, in particular the input element, and / or the external electronic device. This provides a method with which the user can efficiently process various use cases.

The invention also proposes a control unit, in particular a handheld power tool, in particular an impact screwdriver, for carrying out the method as described above.

The invention further provides a hand-held power tool, as described above, for performing a method, as described above, for releasing a screw connection.

Figure list

• 1 eine schematische Seitenansicht einer erfindungsgemäßen Handwerkzeugmaschine;
• 2 ein Flussdiagramm eines erfindungsgemäßen Verfahrens zum Betreiben der Handwerkzeugmaschine;
• 3 ein Drehmoment - Zeit - Diagramm für das erfindungsgemäße Verfahren zum Betreiben der Handwerkzeugmaschine;

The invention is explained below with reference to a preferred embodiment. The drawings below show:

• 1 a schematic side view of a handheld power tool according to the invention;
• 2 a flowchart of a method according to the invention for operating the handheld power tool;
• 3 a torque-time diagram for the method according to the invention for operating the handheld power tool;

Description of the embodiment

1 shows a handheld power tool according to the invention 100 , whereby it is designed here as an exemplary cordless impact wrench. The hand machine tool 100 includes a main output shaft 124 , a tool holder 150 and a striking mechanism 122 . In this embodiment, the hammer mechanism 122 designed as a rotary hammer mechanism. The hand machine tool 100 has a housing 110 with one movement 126 on. The hand machine tool 100 can be mechanically and electrically connected to an energy supply for battery operation for a mains-independent power supply, so that the handheld power tool 100 as a battery-operated hand machine tool 100 is trained. A handheld power tool battery pack serves as the power supply 130 . However, the present invention is not limited to battery-operated handheld power tools, but can also be used in network-dependent, that is to say network-operated, handheld power tools or pneumatically operated handheld power tools.

The case 110 is T-shaped here, although a pistol-shaped housing is also conceivable. The case 110 includes a drive unit 111 and the striking mechanism 122 . The handheld power tool also has 100 a control unit 102 for regulating and / or controlling the drive unit 111 on. The drive unit 111 further comprises an electric motor 114 , which from the handheld power tool battery pack 130 is powered, and a gear unit 118 . The gear unit 118 can be designed as at least one planetary gear. The electric motor 114 is designed in such a way that it can be operated via a manual switch 128 is actuated so that the electric motor 114 can be switched on and off. The electric motor 114 can be any type of motor, such as an electronically commutated motor or a DC motor. The electric motor is advantageous 114 electronically controllable and / or regulatable, so that a reversing operation, as well as a desired speed, can be realized. The structure and the mode of operation of a suitable electric motor are sufficiently known to the person skilled in the art, which is why they will not be discussed in more detail here.

The gear unit 118 is with the electric motor 114 via a motor shaft 116 connected. The gear unit 118 is provided for a rotation of the motor shaft 116 in a rotation between the gear unit 118 and the striking mechanism 122 via a drive member 120 , for example a drive shaft to convert. This conversion is preferably carried out in such a way that the drive element 120 relative to the motor shaft 116 rotates with increased torque, but at a reduced speed. The electric motor is illustrative 114 a motor housing 115 assigned as the gear unit 118 a gearbox 119 . The motor housing 115 as well as the gearbox 119 are exemplary in the housing 110 arranged. However, it is also conceivable that the electric motor 114 and the gear unit 118 directly in the housing 110 can be arranged when the handheld power tool 100 is designed in an "open frame" design.

The striking mechanism 122 is with the drive link 120 connected and includes an impact body 125 that generates sudden, high-intensity rotary impulses. About the impact body 125 these sudden angular impulses are transmitted to the main output shaft 124 , for example a work spindle. The striking mechanism 122 includes a striking mechanism housing 123 , with the striking mechanism 122 also in another suitable housing, such as the gear housing 119 , can be arranged.

The striking mechanism 122 is used to drive the main output shaft 124 educated. On the main output shaft 124 is a tool holder 150 intended. The tool holder is preferred 150 on the main output shaft 124 molded and / or formed. In this embodiment, the tool holder 150 as a polygonal internal receptacle for connection to an insert tool 140 educated. The polygonal internal receptacle is shaped here in the manner of a bit holder with an internal hexagonal receptacle and is designed to be the insert tool 140 in the manner of a screwdriver bit. The application tool 140 has a suitable external hexagon coupling for this purpose 142 on. The type of screwdriver bit, for example of the HEX type, is sufficiently known to the person skilled in the art. However, the present invention is not restricted to the use of HEX screwdriver bits, but rather additional insert tools that appear sensible to a person skilled in the art can also be used, such as HEX drills or SDS-Quick insert tools. It is also possible that the tool holder 150 is designed as a polygonal external receptacle. It is also conceivable that the tool holder 150 is shaped as a polygonal external receptacle for receiving a socket.

The handheld power tool also includes 100 an input unit 170 with an input element 172 to trigger a signal to activate a release operating mode. The input element 172 is designed as a pusher element, not shown in detail. As soon as the input element 172 is operated by the user, the signal for activating the release operating mode is sent out. The signal for activating the release operating mode here has information that the user would like to activate the release operating mode for releasing a fastening element from a fastening support. The fastening element and the fastening support are not shown in detail here. In this embodiment the input unit conducts 170 the signal for activating the release operating mode is wired to the control unit 102 further. When the control unit 102 receives the signal to activate the release operating mode, activates the control unit 102 the release mode of operation for releasing the fastener.

In this embodiment, the handheld power tool comprises 100 additionally a communication unit 160 . The communication unit 160 is designed to have a communication link 180 to manufacture. Here is the communication unit 160 inside the case 110 arranged. The communication unit 160 is designed to receive the signal for activating the release operating mode from an external electronic device (not shown in detail) via the communication link 180 to recieve. By means of the external electronic device, the user can trigger the signal to activate the release operating mode and send it to the communication unit 160 over the communication link 180 to transfer. A transmission of the signal for activating the release operating mode from the external electronic device to the communication unit 160 takes place wirelessly by means of the communication link 180 . The communication unit 160 transmits the signal to activate the release operating mode in a wired manner to the control unit 102 . The control unit 102 receives the signal to activate the release operation mode and activate the release operation mode.

2 shows a flow chart 200 of a method according to the invention for operating the handheld power tool 100 . The procedure 200 releases a screw connection, for example a fastening element from a fastening support. The procedure 200 controls and / or regulates a parameter of the drive unit 111 when operating the hand switch 128 . In this embodiment, the parameter is the drive unit 111 the speed of the drive unit 111 . In one process step 210 receives the control unit 102 the hand machine tool 100 the signal to activate the release operating mode. When the signal for activating the release operating mode is received, a method step 220 the release mode of operation is activated for releasing the fastener. In one process step 230 a direction of rotation of the drive unit is used to loosen the fastening element 111 set. In one option 230a becomes a counterclockwise direction of rotation of the drive unit 111 set when the fastener has a right-hand thread. In one option 230b becomes a clockwise direction of rotation of the drive unit 111 set when the fastener has a left-hand thread. In one option 230c is a maximum speed of the drive unit 111 preset at the factory. In one option 230d the user can set the maximum speed using the input unit 170 to adjust. In one option 230e the user can set the maximum speed by means of the external electronic device. A first torque value M1 the drive unit 111 with a first slope S1 is by means of the control unit 102 in one process step 240 set. The first torque value M1 is in a range from 10% to 80% of a maximum torque value M3 adjustable. The maximum torque value M3 is linked to the maximum speed that has been set. In one option 240a is the first torque value M1 and the first slope S1 preset at the factory. The option 240a therefore enables the control unit 102 directly the first torque value M1 and the first slope S1 adjusts. In one option 240b the user can use the input unit 170 the first torque value M1 and the first slope S1 choose. In one option 240c the user can set the first torque value M1 and the first slope S1 by means of the external electronic device to adjust. As soon as the hand switch 128 is actuated, is in one process step 250 the speed of the drive unit 111 automatically up to the first torque value M1 with the first slope S1 elevated. This takes place essentially independently of a position of the hand switch 128 . The speed is during a period of time T1 automatically increased until the first torque value M1 is achieved, see also 3 . The timespan T1 can be preset at the factory, and they can also be entered by the user using the input unit 170 or the external electronic device can be adjustable. In one option 250a is the speed of the drive unit 111 at a start time t0 when the manual switch is operated 128 preset at the factory. In one option 250b is the speed at the start time t0 using the input unit 170 adjustable by the user. In one option 250c the speed at the start time t0 can be set by the user using the external electronic device. During the first torque value M1 is reached automatically with increasing speed, is the striking mechanism 122 in one process step 260 activated, see also 3 . The striking mechanism 122 is when the starting torque value is reached M0 activated. In one option 260a the speed can be reduced with an activated hammer mechanism. After reaching the first torque value M1 is the speed in one process step 270 up to a second torque value M2 with a second slope S2 elevated. The second slope S2 is less than the first slope S1 . The second torque value M2 will be during a period of time T2 increased, see also 3 . The second torque value M2 is in a range from 50% to 100% of the maximum torque value M3 . The timespan T2 can be in a time range from 5 s to 30 s. The timespan T2 can be done by the user with the help of the input unit 170 or the external electronic device, or the period of time T2 can also be preset at the factory. In one option 270a is the second torque value M2 and the second slope S2 preset at the factory. In one option 270b the user can set the second torque value M2 and the second slope S2 through the input unit 170 to adjust. In one option 270c the user can set the second torque value M2 and the second slope S2 set via the external electronic device. In one option 270d becomes the speed during the period T2 continuously increased. The speed is in an option 270e during the period T2 discreetly increased. After reaching the second torque value M2 or according to the time span T2 the release operating mode ends automatically and the operator or the state of the screw decide how to proceed, see also 3 . Alternatively, in the options 240a , 240b and 240c the first slope S1 by the operator using the hand switch 128 Are defined.

3 shows a torque M - time t diagram 300 for the method of operating the handheld power tool 100 . The torque M is in the unit Nm, whereas the time t is given in seconds. 3 is an idealized representation for the torque M - time t - diagram, in which all influencing factors are neglected. The influencing factors on the torque M-time t-diagram can, for example, be a variable voltage on the drive unit 111 , Influences of the gear unit 118 , the striking mechanism 122 , or the electric motor 114 be. During the period T1 becomes the torque M up to the first torque value M1 with the first slope S1 increased. Where is the time span T1 from the start time t0, when the manual switch is actuated, to a first time t1. As soon as the torque M reaches the starting torque value M0 reached, the striking mechanism 122 activated. In the time span T2 the speed is increased further until the second torque value M2 is achieved. The timespan T2 is from the first point in time t1 to a second point in time t2. The time spans T3 and T4 are after the release operating mode and thus defined by the operator. Over time T3 the speed is kept essentially constant, so that the second torque value M2 is held. The timespan T3 is from the second point in time t2 to a third point in time t3. During the period T4 is the striking mechanism 122 deactivated and illustrates an example of the unwinding of a loosened screw. The speed is kept essentially constant. The timespan T4 is from the third point in time t3 to a fourth point in time t4, the fourth point in time t4 being an end point in time.

Once the starting torque value M0 is reached, the striking mechanism starts 122 on and generates torque pulses with increasing speed. With the help of the blows of the striking mechanism 122 can be a pulse for an additional torque on the main output shaft 124 and the tool holder 150 be generated. After every stroke of the striking mechanism 122 is on the main output shaft 124 and the tool holder 150 the starting torque value M0 until the striking mechanism 122 generates a next torque pulse.

QUOTES INCLUDED IN THE DESCRIPTION

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Patent literature cited

• DE 202011002192 U1 [0002]

Claims (14)

A method for operating a handheld power tool (100), in particular a rotary impact wrench, with a drive unit (111), a manual switch (128), a control unit (102) and with a release operating mode for releasing a screw connection, in particular a fastening element from a fastening carrier, in which at the actuation of the manual switch (128) a parameter of the drive unit (111) is at least partially automatically controlled and / or regulated. Procedure according to Claim 1 , characterized in that in a method step the parameter of the drive unit (111) is at least partially automatically controlled and / or regulated after an impact mechanism (122), in particular rotary impact mechanism, of the handheld power tool (100) has been activated. Procedure according to Claim 1 or 2 , characterized in that the release operating mode is carried out from a first point in time t1 to a second point in time t2, the second point in time t2 following the first point in time t1. Procedure according to Claim 1 or 2 , characterized in that the release operating mode is carried out from a start time t0 to a second time t2, the drive unit (111) being activated at the start time t0. Procedure according to Claim 3 or 4th , characterized in that the release operating mode is deactivated after the second point in time t2. Procedure according to Claim 5 , characterized in that after reaching a first torque value M1, a speed up to a second torque value M2 of the handheld power tool (100) is changed with a second slope S2. Method according to one of the preceding claims, characterized in that the parameter is a speed of the drive unit (111), the speed being assigned at least one torque M, and the torque M at least partially automatically up to a first torque value M1 of the handheld power tool (100) is changed with a first slope S1 by changing the speed of the drive unit (111). Method according to one of the preceding claims, characterized in that after the second torque value M2 has been reached, the speed is kept essentially constant, in particular until the hammer mechanism (122) is deactivated. Method according to one of the preceding claims, characterized in that the first torque value M1 and the second torque value M2 are preset in the control unit. Method according to one of the preceding claims, characterized in that the first torque value M1 and the second torque value M2 can be set in the control unit. Method according to one of the preceding claims, characterized in that a counterclockwise direction of rotation of the drive unit (111) is set in order to loosen the screw connection. Method according to one of the preceding claims, characterized in that a clockwise direction of rotation of the drive unit (111) is set in order to loosen the screw connection. Control unit (102) for performing the method according to at least one of the preceding claims. Hand machine tool (100) for performing the method according to at least one of the Claims 1 to 12th .

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